There are many applications in which it is desirable or necessary to simultaneously transmit and receive. Such applications include coherent repeaters and transponders, as well as some electronic warfare and communication systems.
Cancellation circuits are needed to enable simultaneous transmit and receive (STAR) functionality. In the prior art there are components and systems for cancellation circuits; however, these prior art circuits do not have the desired power handling, linearity and bandwidth needed for high performance systems.
Such prior art systems have been described in the following references.